wild ox vs ox

wild ox and ox both are nouns.

Word	Noun	Adjective	Verb	Adverb
wild ox	Yes	No	No	No
ox	Yes	No	No	No

As nouns, wild ox and ox are synonyms defined as:

wild ox and ox: any of various wild bovines especially of the genera Bos or closely related Bibos

wild ox (noun)	ox (noun)
any of various wild bovines especially of the genera Bos or closely related Bibos	any of various wild bovines especially of the genera Bos or closely related Bibos
	an adult castrated bull of the genus Bos; especially Bos taurus